During the 1970s, KEF published a number of technical articles in a range called ‘KEFTOPICS’. They were designed to give an insight into the real world of loudspeaker design and manufacturing. At a time when practical design information was limited, they were an excellent resource for anyone looking to improve their understanding of loudspeakers. The techniques and procedures described in these articles formed the basis of the KEF methodology, which is still in practice today, and because of the fundamental nature of the topics described, much of the information is just as relevant today as it was then. The topics covered in the range include crossover filters, production consistency, overload protection, high efficiency with small enclosures and the design story behind some of KEF’s famous loudspeakers, such as the Reference Series Model 105